President Donald Trump will close tax-free loopholes in low-value packages, pushing prices higher for customers of companies such as Shein and Temu.

China's online retail giant relies on so-called "minimum" exemptions to sell and ship low-value items directly to the United States without paying duties or import taxes.

Proponents of the vulnerability apply to parcels worth less than $800 (£600), believing it helps simplify customs processes.

But both Trump and his predecessor, Joe Biden, said it hurt U.S. businesses and was used to smuggle illegal goods, including drugs.

de minimis is a Latin word that literally means "smallest".

In this case, it refers to a US trade rule enacted in 1938 that allows visitors returning to the United States to bring up to $5 worth of souvenirs (about $112) from abroad without declaring their customs.

In the 21st century, it allows retailers to ship packages worth less than $800 to U.S. customers without having to pay responsibilities or taxes.

According to the country’s Customs and Border Patrol (CBP), goods under exempt accounts account for more than 90% of all goods entering the United States.

Chinese online retailers like Shein and Temu have benefited greatly from the vulnerability.

Both platforms have attracted marketing lightning from millions of customers who showcase their super low prices

It is De Minimis waivers that help them offer such a cheap deal.

Shein and Temu did not immediately respond to the BBC's request for comment.

However, in a nearly identical statement last month, competitors said operating expenses rose due to the latest changes in global trade rules and tariffs, adding that they will make a “price adjustment” starting April 25.

In February, Trump briefly closed the loophole.

The pause was quickly paused as customs inspectors, delivery companies and online retailers struggled to adapt to such a significant change in a short time.

During the period when the initial suspension was exempted, the U.S. Postal Service temporarily stopped accepting packages from mainland China and Hong Kong.

The executive order that announced the latest move said it aims to address the illegal import of synthetic opioids such as fentanyl.

It said many Chinese shippers use deceptive practices to hide illegal substances in low-value kits to “utilize minimum exemptions.”

It added: "The drugs kill thousands of Americans every year, including 75,000 deaths each year, causing only fentanyl."

Those packages from mainland China and Hong Kong will perform their duties from May 2, and the charges will rise next month.

This idea is not new. Last year, the Biden administration proposed rules aimed at stopping the “abuse” of exemptions.

It said: "The growing growth of De Minimis cargo makes the target increasingly difficult and stops illegal or unsafe cargoes."

This move is in line with Trump's policy to suppress goods in China.

Since returning to the White House in January, Trump has imposed taxes on China's import taxes of up to 145%. His administration said in April that when new tariffs are added to existing tariffs, taxes on certain Chinese goods could reach 245%.

U.S. authorities also accuse companies such as Temu and Shein of the success of pressure on border authorities as the number of parcels entering the U.S. soared from about $140 million a decade ago to more than one billion last year.

Even before import taxes are imposed on these parcels, U.S. consumers will see prices rising.

Shein and Temu began investing prices for U.S. customers by the May 2 deadline “due to the latest changes in global trade rules and tariffs.”

The U.S. Action Forum is a direct policy group that estimated last year that getting rid of the waiver would result in “$8 billion to $30 billion in annual fees that will eventually be transferred to consumers.”

Chinese online retailers have also benefited from similar rules in the UK and EU to attract millions of customers.

There are concerns that the U.S. crackdown could cause China to flood the UK.

In a move reflecting the U.S. action, the UK announced a review of low-value imports entering the country.

In the UK, current rules allow international retailers to send currency sales to the UK without incurring import taxes worth less than £135.

Prime Minister Rachel Reeves said cheap goods “weakened British streets and British retailers”.

The EU also called on member states to abolish tax exemption for lands of less than €150 (£127.50; $169.35).

In February, the EU raised new fees for packages delivered to the group among online retailers.

This means that consumers in the UK and EU may also see prices rising soon.

Check parcels arriving in the United States in the same way as other goods, including checking for illegal substances. Officials say most synthetic opioids enter the country through the border with Mexico.

Some experts believe that ending the exemption will not help curb illegal drugs and will not solve the challenges facing U.S. manufacturers.

People also fear the move will create more work for U.S. border officials, who are trying to stop drug trafficking.

According to the Parent Trade Association (NFTC), the removal of the minimum exemption will “transfer the focus of the CBP to the border where the vast majority of illegal substances and products enter the country’s borders”.

It added: “CBP needs to hire and train new personnel to get millions of agents, or to move agents from the already burdened southern border.”